Machine tool



y 1955 E. J. BERLO 3,181,382

MACHINE TOOL Original Filed June 24, 1959 4 Sheets-Sheet 1 L In K H! w QE N 1 E E E m w E lIIlllIllIIIllllllllllllllllllllll INVENTOR. ERNEST JBER/.0 O BY A 7' TORNEV y 4, 1965 E. J. BERLO 3,181,382

MACHINE TOOL Original Filed June 24, 1959 4 Sheets-Sheet 2 INVENTOR.ERNEST J. BERLO A T TORNE V E. J. BERLO MACHINE TOOL May 4, 1965Original Filed June 24, 1959 4 Sheets-Sheet 5 INVENTOR. ERNEST J. BERLOA TTORNEV May 4, 1965 Original Filed June 24, 1959 E. J. BERLO MACHINETOOL 4 Sheets-Sheet 4 INVENTOR. ERA/EST J. BERLO ATTORNEY United StatesPatent 2 Claims. 01. 74-217 This invention relates generally to machinetools, and more particularly to an improved combination milling machineand lathe. The present application is a division of application SerialNo. 822,526, filed June 24, 1959, and now abandoned.

Heretofore lathes have not been well-suited for doing milling workbecause their various parts have been designed primarily for Verticalthrust loads developed by the cutting tool as it engages the workpiece,whereas a milling operation using the lathe headstock as a tool holderdevelops horizontal thrust as Well as those in a vertical direction.Others have sought to provide machine tools upon which both milling workand turning work may be performed, but none has the necessary rigidityrequired for milling operation. This is particularly true with respectto lightweight bench-type tools designed for the home craftsman.

It is therefore an object of this invention to provide a lightweightbench-type machine tool which has the necessary rigidity and providesthe accuracy required for milling operations, and yet which may be usedfor simple turning work.

It is another object of this invention to provide in a machine tool asingle vertically shiftable headstock utilized both as a spindle onwhich turning work may be secured and as a spindle for holding a millingcutter.

It is a further object of this invention to provide an improved multiplebelt speed reducer adapted for use with a vertically shiftableheadstock.

These and numerous other objects and advantages may become more apparentfrom the following detailed description when considered in connectionwith the accompanying drawings. The present invention is comprised of apair of Ways disposed in planes perpendicular to one another, avertically shiftable headstock which constitutes both a milling head anda lathe spindle, a tailstock, and a horizontally shiftable carriagewhich constitutes either a work support or a tool rest. Referring to thedrawings:

FIG. 1 is a top view of a machine tool emboding features of the presentinvention and having several parts broken away to more clearlyillustrate the structure;

FIG. 2 is a side elevational view of this particular embodiment;

FIG. 3 is an elevational view of the headstock end of the presentinvention showing the motor drive;

FIG. 4 is a partial perspective view of the multiple-belt speed reducer;

FIG. 5 is a cross section of the speed reducer pulleys taken along line5-5 in FIG. 4;

FIG. 6 is a cross-sectional view of the tailstock assembly taken alongline 66 of FIG. 1; and

FIG. 7 is a top view of the unit with a barstock collet mounted on thespindle and a compound tool rest mounted on the cross-feed table.

Referring to the drawings in detail wherein like numerals have beenemployed to designate similar parts throughout the various figures, itwill be observed that the particular embodiment illustrated comprises arigid bed 1 which is typical of small bench-type lathes. The bed 1 restsupon a bench 2 or table of convenient working height. A tailstockassembly, referred to generally as 3, is mounted upon horizontal ways 4carried on the bed 1. Vertical ways 5 are rigidly mounted on the bed 1with the face of the vertical ways lying in a plane perpendicular to thehorizontal ways 4 and parallel to the longitudinal axis thereof.

A vertically shiftable headstock assembly 6 is mounted on the verticalWays 5 and a carriage assembly referred to as 7 is slida'bly mounted onthe horizontal ways 4.

The carriage assembly 7 comprises a saddle 8 dovetailed on thehorizontal ways 4 upon which is supported a cross-fed milling table 9.As illustrated in FIG. 1 the table 9 is fed transversely across thehorizontal ways 4 by means of the cross-feed screw 10 rotated by thecrossfeed handwheel 11 and fitting into the cross-feed nut 12 secured tothe saddle 8. A vise 12a is mounted on the cross-fed table 9 and holds aworkpiece during milling operation. Alternatively, the cross-feed table9 may carry a compound tool rest 12!), as illustrated in FIG. 7, toperform turning operations.

The carriage assembly 7 is moved along the horizontal Ways 4 by means ofa lead screw 13 mounted adjacent the horizontal ways 4 and extending thefull length thereof. The lead screw 13 is manipulated by the lead screwhandwheel 14 conveniently mounted at the tailstock end of the horizontalways 4. The lead screw 13 engaged a threaded lug 15 depending from thesaddle 8 so that rotation of the handwheel 14 moves the carriageassembly longitudinally along the horizontal ways 4.

The tailstock assembly 3, appearing in section in FIG. 6, is of a typethat will be familiar to those skilled in this art. The assembly has asegmented base 16 which dovetails over the horizontal ways 4. Atailstock clamp screw 17 passes through the base of the tailstock and bymeans of the locking nut 18 secures the segmented portion '19 of thetailstock base 16 to the ways 4 thereby holding the tailstock assembly 3firmly in a particular position. The tailstock clamp screw 17 is pivotedby the handle 20. It will he observed in FIG. 6 that when the segmentedportion 19 of the tailstock base has been loosened, the entiret-ailstock assembly 3 can be pivoted off the horizontal ways 4 at anyposition of the assembly, rather than having to be removed oil the endof the Ways.

The tailst-ock center 21 is mounted in a ram 22 and is moved axially bymeans of the tailstock handwheel 23. The ram 22 is mounted in thesplit-frame 24 and is secured in position by the ram clamp screw 25.

The headstock assembly 6 comprises a housing 26 dovetailed on thevertical ways 5. The assembly is moved vertically along said ways bymeans of the vertical feed screw 27 operated by the vertical feedhandwheel 28. The headstock housing 26 carries a driven spindle 29 onone end of which is mounted a step-cone pulley 3d. The spindle 29isprovided with a collet for handling barstock, a faceplate or a chuckfor handling irregular work pieces, or with a spring chuck and colletfor securing an end mill or other milling cutters. A spring chuck andcollet 31a for securing the end mill 32a is illustrated in FIGS. 1, 2and 3. FIG. 7 illustrates a collet 31b in place for handling barstock.The position of the headstock housing is secured by the headstock clamp33. The lowermost position is determined by the stop 34, FIG. 2, atwhich position the axis of the spindle 29 is coaxial with that of thetailstock center 21.

As illustrated in FIG. 3, the spindle 29 is provided with a V-belt 35extending from any one of the pulleys of the step-cone pulley 30 to apulley 36 mounted on the driving motor 37. In order to properly tensionthe belt 35, the driving motor 37 is mounted on a bracket 38 pivoted asat 39 from any rigid support such as the bench 2 illustrated herein. Inthis manner the weight of the motor itself under the force of gravitytensions the V belt drive.

It will be apparent that since the cutting speeds required for millingand ordinary lathe work vary considerably for a given Work material andtool material, the

spindle speed must be reduced substantially when fitted V with a millingcutter and performing a milling operation.

A multiple-belt speed reducer, illustrated in FIG. 4, is used to effectthis speed reduction. During the milling operation the single V-belt 35is rernovedand replaced by the multiple-belt and pulley system havingthe same overall length from the motor pulley 36 to the step-cone pulley30 as the single belt 35. This speed reducer assembly comprises a firstbelt 40 extending from the pulley 36 mounted on the motor shaft to anintermediate pulley assembly 41 which is composed of a large diameterpulley 42 and a smaller diameter pulley 43 cast as a unit, as appears inFIG. 5. The unitary pulleys 42 and 43 carry a stub shaft 44 upon 'Whichis pivoted a second small diameter pulley 45. A second belt 46 extendsfrom the pulley 43 to the step-cone pulley 30 on the spindle and a thirdbelt 47, which functions entirely as a means for stabilizing the system,extends from the pulley 45 to .any smaller sheave on the step-conepulley 30, as illustrated in FIG. 4. The belt 47 is provided to preventthe pulley assembly 41 from twisting under the turning moment developedby belts 40 and 46. With the foregoing multiple-belt speed reducereffective speed reductions may be accomplished at a minimum of cost andwithout auxiliary gearing and countershafts generally necessary to.

. in which is secured an end mill 32a. The workpiece is held intheremovable Vise 12a carried on the cross-feed table 9. The Vise 12a is ofthe familiar universal type and is secured in a hole 48 provided,therefor 'in the table by means of a pair of setscrews. 49." The vise12a is replaceable with a compound tool rest 12b carrying a cutting tool50 of a type familiar to those skilled in this art as shown in FIG. 7.In conjunction with the compound tool rest 12b, the spindle 29 isprovided with a collet, faceplate, or chuck for holding the workpiecewhen turning work is performed. FIG. 7 illustrates this setup with abarstockworkpiece 51 secured inthe colletx31b and supported on thetailstock center 21.

standing only, and no unnecessary limitations should be understoodtherefrom, for modifications will be obvious to those skilled in theart.

I claim:

1. A multiple belt drive means comprising in combination a first shaft;a first pulley mounted on and rotatable with said first shaft; a secondshaft; a step-cone pulley mounted on and rotatable with said secondshaft; a stub-shaft floatingly suspended between said first and secondshafts; a first end pulley rotatably mounted on said stub-shaft; asecond end pulley mounted on said stub-shaft and rotatable therewith; anintermediate pulley mounted between said first and second end pulleys,on and rotatable with said stub-shaft; a first belt embracing said firstpulley andsaid intermediate pulley; a second belt embracing said firstend pulley and one step of said step-cone pulley; a third belt embracingsaid second end pulley and another step of said step-cone pulley wherebythe floating suspension of said stub-shaft, and the pulleys thereon, iseffected by said first, second and third belts.

2. A multiple belt speed reducer comprising a drive shaft; a firstpulley mounted on and rotatable with said drive shaft; a driven shaft; astep-cone pulley mounted I on and rotatable with said driven shaft; anintermediate pulley assembly floatingly suspended between said drive anddriven shaft, including a stub-shaft, a first end pulley rotatablymounted on said stub-shaft, a second end pulley mounted on and rotatablewith said stub-shaft, and an intermediate pulley mounted between saidfirst and secend end pulleys on and rotatable with said stub-shaft andhaving a diameter greater than the diameter of said first pulley and ofsaid second end pulley; a first belt The foregoing detailed descriptionof an. embodiment of the present invention is given for clearnessofunderembracing said first pulley'and saidintermediate pulley; a secondbelt embracing said secondend pulley and one step of said step-conepulley; and'a third belt embracing said first end pulley and anotherstep of said step-cone.

pulley whereby said first, second and third belts floatingly suspendsaid intermediate pulley assembly between said drive and driven shafts.

References Cited by the Examiner V UNITED STATES PATENTS WILLIAM W.DYER, JR., Primary Examiner.

1. A MULTIPLE BELT DRIVE MEANS COMPRISING IN COMBINATION A FIRST SHAFT;A FIRST PULLEY MOUNTED ON AND ROTATABLE WITH SAID FIRST SHAFT; A SECONDSHAFT; A STEP-CONE PULLEY MOUNTED ON AND ROTATABLE WITH SAID SECONDSHAFT; A STUB-SHAFT FLOATINGLY SUSPENDED BETWEEN SAID FIRST AND SECONDSHAFTS; A FIRST END PULLEY ROTATABLY MOUNTED ON SAID STUB-SHAFT; ASECOND END PULLEY MOUNTED ON SAID STUB-SHAFT AND ROTATABLE THEREWITH; ANINTERMEDIATE PULLEY MOUNTED BETWEEN SAID FIRST AND SECOND END PULLEYS,ON AND ROTATABLE WITH SAID STUB-SHAFT; A FIRST BELT EMBRACING SAID FIRSTPULLEY AND SAID INTERMEDIATE PULLEY; A SECOND BELT EMBRACING SAID FIRSTEND PULLEY AND ONE STEP OF SAID STEP-CONE PULLEY; A THIRD BELT EMBRACINGSAID SECOND END PULLEY AND ANOTHER STEP OF SAID STEP-CONE PULLEY WHEREBYTHE FLOATING SUSPENSION OF SAID STUB-SHAFT, AND THE PULLEYS THEREON, ISEFFECTED BY SAID FIRST, SECOND AND THIRD BELTS.